The present invention relates to a charge control device that changes a charge completion voltage or an abnormality determination voltage according to the temperature of a battery.
Conventionally, in a lithium ion battery, a temperature range at the time of charging is classified to three regions, i.e., a low temperature region (T1 to T2), a normal temperature region (T2 to T3), and a high temperature region (T3 to T4), as illustrated in FIG. 9. Per region, a maximum voltage Vmax of the battery is defined (for example, see Japanese Unexamined Patent Application Publication No. 2009-55729).
Therefore, a charge control device of this type that controls charging of a battery is adapted to set a charge completion voltage as a target voltage during charging and an abnormality determination voltage for determining abnormality of the battery, per the temperature range, so that the battery voltage during charging does not exceed the maximum voltage Vmax defined as above.